In this Wednesday, Feb. 7, 2018 photo, Hesham Genena, Egypt's former top auditor who suffered serious injuries during an apparent kidnapping attempt, talks during an interview with the Associated Press at his home in Cairo, Egypt. CAIRO —

Egypt's former anti-graft chief was arrested on Tuesday, his lawyer said, the latest development in an upheaval that has roiled the country ahead of next month's presidential election.

The lawyer, Ali Taha, told The Associated Press that Hesham Genena was arrested by police at his home in a Cairo suburb and was later handed over to military prosecutors for questioning.

The arrest came a day after the military said it would take action to safeguard its "honor and dignity" following incendiary comments by Genena in which he claimed in a television interview that former military chief of staff Sami Annan was in possession of documents incriminating the country's "leadership."

Genena, who was to be one of Annan's two top campaign aides, led Egypt's top watchdog agency until el-Sissi fired him in 2016. He is the latest election-related casualty in what appears to be an intensifying campaign against dissent ahead of the vote.

In the TV interview, Genena said the alleged documents are kept abroad and would be released if any harm came to Annan.

Annan himself was arrested by the military last month, days after he declared his intention to run for president. The military said he faced charges of incitement against the military and forgery.

Annan was among a string of potentially serious challengers to the incumbent, general-turned-president Abdel-Fattah el-Sissi, to be arrested or forced out of the race.

El-Sissi is virtually certain to win the March vote, with his only challenger an obscure politician and one of his most ardent supporters.

Moussa Mustafa Moussa entered the race in the eleventh hour, sparing el-Sissi and his government the deeper embarrassment of a one-candidate election.

But the pre-election turmoil is not confined to would-be candidates.

Leaders of opposition parties who called for a boycott of the vote are being investigated on allegations they are seeking to destabilize the country.

Over a dozen international and regional rights groups issued a joint statement on Tuesday, saying that the upcoming election does not meet the "minimum requirements" for a fair and free vote and called on Cairo's Western allies to denounce the "farcical" election.

The 14 groups, which include human Rights Watch and the International Commission of Jurists, said el-Sissi's government has "suppressed freedoms, arrested potential candidates and rounded up their supporters."

El-Sissi has since 2013 overseen a wide crackdown on dissent, jailing thousands of Islamists and also scores of activists behind the 2011 uprising that toppled autocrat Hosni Mubarak. The crackdown followed the July 2013 ouster by the military, then led by el-Sissi, of Egypt's first freely elected civilian President Mohamed Morsi of the now-banned Muslim Brotherhood.

Elected to office the following year, el-Sissi has since silenced most critics in the media, rolled back freedoms won by the 2011 uprising and placed draconian restrictions on demonstrations and the work of rights groups.

"The Egyptian government has trampled over even the minimum requirements for free and fair elections for the planned March 26-28 vote," the 14 groups said in a statement. El-Sissi's government "has relentlessly stifled basic freedoms and arrested potential candidates and rounded up their supporters."

"Seven years after Egypt's 2011 uprising, the government has made a mockery of the basic rights for which protesters fought," it added.